Polysiliconin situphosphorus doping control over large concentration range using low temperature, low pressure chemical vapour deposition growth process

Electrical properties of polysilicon nanowires for device applications

“…Beyond that range resistivity decreases following the same doping effect as in crystalline silicon. The shape of the curve, quite similar to previously observed results for in-situ doped polysilicon layers [12,13], indicates that polysilicon NWs doping effect is in accordance with the Seto's theory [14]. In this model, the conduction is thermally activated.…”

“…In this model, N* is related to the quality of the polysilicon layer both through the defects density at the grain boundaries and the lateral grain size. In our case N* ~ 10 18 cm -3 , corresponding to the value obtained for previous studies [12][13][14]. These results show that this electrical conduction model can be applied for polysilicon NWs at high temperatures.…”

“…Our results highlight the good control of the doping level on the 100 mn long curvature radius polysilicon NWs over a wide range, with a doping effect similar to polysilicon layer [12][13][14]. This study shows that despite the high defects density within these polysilicon NWs, there is no significant doping species segregation at grain boundaries affecting doping efficiency.…”

“…The in-situ doping level is controlled by adjusting the PH 3 /SiH 4 mole ratio varying from 0 (undoped film) to 1.2×10 -3 (heavily doped film). The corresponding incorporated phosphorus atoms concentration C p , previously determined from SIMS (Secondary Ions Mass Spectroscopy) analysis, varies from 2×10 16 cm -3 to 2×10 20 cm -3 [12]. Silicon films are deposited in an amorphous state at 550 °C and 90 Pa, and then crystallized by a thermal annealing in vacuum at 600 °C during 12 hours.…”

Influence of the Doping Gas on the Axial Uniformity of the Growth Rate and the Electrical Properties of LPCVD In-Situ Doped Polysilicon Layers

“…A complete study of the phosphorus doping of polysilicon under the experimental conditions described above has been carried out and the results are reported elsewhere [4,5]. No significant inhomogeneities are observed.…”